Question

A known volume of 0.1 M solution of hydrobromic acid is reacted with 25 mL and the concentration of the potassium hydroxide is calculated from the stoichiometry of the reaction.

Answer 1

To calculate the concentration of the original hydrochloric acid solution sample, you can use the stoichiometry of the reaction between HCl and NaOH. The moles of HCl can be determined by multiplying the volume of NaOH used by its concentration, and then the concentration of the hydrochloric acid solution sample can be calculated using the moles and volume of the sample.

Step-by-step explanation:

To calculate the concentration of the original hydrochloric acid solution sample, you can use the equation:

HCl (aq) + NaOH (aq) -> NaCl (aq) + H2O (l)

From the balanced equation, we can see that the ratio of HCl to NaOH is 1:1. Therefore, the moles of HCl can be calculated by multiplying the volume of NaOH used (in L) by its concentration in Molarity.

Example:

1. Convert the volume of NaOH to L: 31.416 mL = 0.031416 L
2. Calculate the moles of HCl: 0.031416 L * 0.1234 M = 0.003875 moles
3. Use the moles of HCl and the volume of the hydrochloric acid solution sample to calculate its concentration: Concentration = (0.003875 moles / 0.2000 L) * 1000 = 19.38 M